Build an EASY 10 Meter (28 MHz) Vertical Antenna for DX!

It's way better than trying to TX without an antenna

 

Thanks. I made a second one out of RG58 A/U, as it's more flexible and has 95% braid and trimmed to get 1.5:1 from 28.365-29.445 and the air choke is 6 turns on an 83mm form, which is a tad below 4 μh. This week made DX contacts to Scotland, Wales, Sardinia, Cuba, and Mexico, with reports of 5/5-5/9 from the Anytone 5555 PLUS/N with 40W. With the first one I think the 16 turns was too much and became capacitive creating waves of noise in RX. I didn't notice this with the newer one. May be it's a better mousetrap; hi hi.

 

SWR means nothing in regards to the efficiency of an antenna. Contacts mean nothing in regard to how well an antenna radiates.

Years ago this was proven by a prominent 160 meter DX operator on the West Coast. He installed a light bulb at the top of his tower and loaded his transmitter into it.

Worked DXCC with it.

With a low SWR and a flashing light. ERP was VERY low. But, you don't need a lot of power.

Great contact you made. You'll find 10 will operate with nearly nothing for an antenna and minimal radio.


I'm mentioning these things because of the reports being given here. I operate with SWRs in the 10s. With open wire line it doesn't matter. With coax, it would. It doesn't make a difference to the antenna, as long as you can feed power into it.

Don't think SWR matters to the efficiency of the antenna. Don't think a contact means your antenna is killer. Neither means anything.

--Shane
WP2ASS / ex KD6VXI

 

"Creating waves of noise in RX"... Not sure what that means.

When you have a coaxial cable, you have 3 conductors. The center conductor, the inside of the coax shield and the outside of the coax shield. With an air choke, especially, you can create a series resonant circuit. I'll get back to this.

Anyway, the RF from your transmitter travels down the center conductor. The inside of the braid / foil shield makes sure of this. Noise and all kinds of crap are on the outside of the braid. If you don't have a choke AT THE FEEDPOINT then you risk noise ingress from the outside of the shield then coupling to the inside of the shield and back to your transmitter. No bueno.

These sleeve antennas are HORRIBLE for this. Anyway.

If the choke is series resonant then it can INCREASE the voltage of the noise on the outside of the shield before it comes back through the inside, owing to no choke at the feedpoint.

Put a choke at the feedpoint, all of a sudden the antenna has issues with swr because you then have a half of a dipole.

Nature of the beast.

Incidentally, these are pretty much the same thing as the Shakespeare Big Stick of CB fame of the 80s.

--Shane
WP2ASS / ex KD6VXI

 

Great to hear from a fungi. Darn there's that goofy word prediction again. Well, you know what I mean. You're an encyclopedia full of information. Just wondering how are you at parades?

 

Hi Fred- Or, build a very simple 10m (or 6m) vertical dipole.. broadbanded with a near perfect counterpoise.. 73

 

I may have missed this in the video but what is the diameter of the pvc?

 

Can I substitute copper shield rg 59 for rg 58?

 

I’ve found “umbrella stands” at Walmart, Lowe’s, Home Depot or the neighborhood outdoor furniture store.